The purpose of this study is to investigate the breakdown properties in joint interface of power cables with heat treatment. The specimens have the structure of XLPE/EPDM interface like the joint of distribution power cable. The breakdown characteristics of the SLPE/EPDM joint were studied with crosslinking by=products. AC breakdown voltages were measured with heat treatment time and interfacial materials and crosslinking by-products as testing factors. This study has shown that crosslinking by-product gases play an important role at the insulation properties of cable joints by heating. The dielectric strength shows the lowest values at 4 hours heat treatment. The AC breakdown strength in the untreated sample was increased with heat treatment time.

Mo-tip field emitter arrays(FEAs) were fabricated by conventional Spindt process and their life time characteristics and failure mode were evaluated. The fabricated Mo-tip FEA could generate at least emission current for about 320 persistently under a constant gate bias of 140 V and was finally destroyed through self-healing mode. Thin diamond-like carbon films were coated on the M-tip by plasma-enhanced CVD and the dependence of emission properties upon the DLC thickness was investigated. By DLC coating, the turn-on voltage and emission current were appeared to be improved whereas the current fluctuation was increased in the DLC thickness range of .

After etching Al-Cu alloy films using plasma, a corrosion phenomenon on the metal surface has been studied with XPS(X-ray pheotoelectron spectroscopy) and SEM (Scanning electron microscopy). In Al-Cu alloy system, the corrosion occurs rapidly on the etched surface by residual chlorine atoms. To prevent the corrosion, plasma treatment subsequent to the etch has been carried put. A passivation layer is formed by fluorine-related compounds on the etched Al-Cu surface after treatment, and the layer suppresses effectively the corrosion on the surface as the treatment in the pressure of 300m Torr.

We have fabricated a LDD structured polysilicon thin film transistor with low leakge current and the optimized LDD length has been obtained. The device performance is improved is improved by hydrogen passivation process. The on.off current ratio of poly0Si TFT s with and LDD length is much higher than that of conventional structured device due to the decrease of leakege current. The optimized LDD length may be from the experimental data such as on/off current ratio, threshold voltage and hydrogenation effect.

Thin film deposition of InN, which is a less-studied III-nitride compound semiconductor because of the difficulty if crystal growth, was performed by rf reactive sputtering method using In target and reactive gas. The structrual, electrical, and optical properties of the produced films were measured and disussed according to the sputtering parameters such as deposition pressure, rf power, and substrate temperature. From the result of deposition pressure, rf power, and substrate temperature, we could obtain optimal conditions of 5m Torr, 60W, for preparing InN thin film with high crystallinity, low carrier concentration, and high Hall mobility. The carrier concentration, Hall mobility, and optical bandgap of the fabricated InN thin films at optimal condition were ｓ, and 1.912eV, respectively.

Thin films of PLZT were prepared on indium tin oxide(ITO) coated glass substrates by sol-gel process and annealed by rapid thermal annealing(RTA) at for 5 minutes. The crystal structure of PLZT thin films were investigated for a different Zr mol% content. XRD results showed that the crystallographic structure was transitted from tetragonal to rhombohedral structure as Zr mol% increased. Raman spectroscopy results showed that the bands of spectra became broader as the amount of Zr mol% increased and two crystal phase coexisted at 2/55/45 PLZT film. Raman spectroscopy was useful for crystal structure analysis of PLZT thin films.

(PZT, PST, PT)/ YBCO structured have been grown on single crystal using in-situ Nb:YAG pulsed laser deposition technique. The optimum conditions of fabrication for high quality films have been established under various oxygen pressure. TBCO was used as a metallic electrode for polarizing ferroelectric thin fillms. Lattice mismatch of these materials were found to be with in 3%. As a result XRD patterns and rocking curves, (PZT, PST, PT)/ YBCO multiayered thin films on substrates showed preferred orientation to c-axis. For invastigation on electrical properties of ferroelectric thin films, remanent polaiztion and coercive field were measured for three samples. At each optimum condition, they showed the values of P_r=60 \mu C/cm^2 and E_c=240kV/ cm for PT, 30\mu C/cm^2 and 105kV/cm for PZT, 1.5\mu C/cm^2$ and 15kV/cm for PST. Frequency dependence of dielectric properties of ferroelectric thin fillms was also investigated. As a result, it showed the frequency dependence was relatively small in the range of 10Hz~10kHz.

(x=0.0, 0.025, 0.1, 0.2) for negative temperature coefficient (NTC) thermistor was prepared by calcination at and sintering at form 1100 to with intervals. The best linear property was obtained in the Mn-based sample sintered at with x=0.0 composition. Temperature coefficient of resistance, , was in the Mn-based sample, in the MM-based sample, and in the Mg-based sample. thermistor parameter, B, was in the range of 2665~7780 K. The results show the possibility that Mn-Ni-Co based thermistor could be substituted by the composition used in this study.

Diamond thin films were deposited on Si substrate using mixed gas by RF plasma CVD. Prior to deposition, the substrate surface was mechanically scratched with the diamond paste of to improve the density of nucleation sites. The microstructure of diamond films deposited with methane(0.5%~2%) at the reaction pressure ranging from 20 torr to 50torrr were studied by a scanning electron microscope. It was observed in the deposited diamond films that the nucleation density decreased and crystallinity increased with decreasing the methane concentration. However, the nucleation density and crystallinity were decreased with decreasing the process pressure.

A low loss x-cut optical waveguide was fabricated by Yi in-diffusion, and the properties of guided-mode and the total insertion loss of the pigtailed waveguide with polarization maintaining fiber(PMF) were measured at optical wavelength 1550nm. for forming the waveguides, the parameters of diffusion, Ti thickness, waveguide line-width, length, diffusion temperature, time and atmosphere were set , , 3.3cm, , 8 hours and wet bubbled oxygen, respectively. And then after the polishing and piatailing, it showed that the total insertion loss was -4.1dB for TM mode, -5.5dB for TE mode, and mode size, that is, the horizontal/ vertical size were for TM mode, for TE mode.

Recently a few MJ superconducting magnetic energy storage ( SMES) devices become commerci-ally available as one of the energy storage devices for uniterruptible power supply (UPS) systems. For such a ( SMES) devics, a few kA class superconducting cables with high current density, high stability and excellent pulse characteristics are required. To acquire data for the superconduction cables related to design and fabrication of a 0.7 MJ SMES device, we tested critical currents and quench characteristics for several winding tensions and various remping rates especially. It is shown from the results that winding tensions have much influence on quench currents of the SMES devices.

The numerical model that can describe the ignition of pseudospark discharge using hybrid fluid-particle(Monte Carlo )method has been developed. This model consists of the fluid expression for transport of electrons and ions and Poisson's equation in the electric field. The fluid equation determines the spatiotemporal dependence of charged particle densities and the ionization source term is computed using the Monte carlo method. This model has been used to study the evolution of a discharge in Argon at 0.5 torr, with an applied voltage if 1kV. The evolution process of the discharge has been divided into four phases along the potential distribution : (1) Townsend discharge, (2) plasma formation, (3) onset of hollow cathode effect, (4) plasma expansion. From the numerical results, the physical mechanisms that lead to the rapid rise in current associated with the onset of pseudospark could be identified.